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Zhou X, Zhang J, Sun M, Yang HQ, Wang Z, Yang J, Huang GB. Hexafluoroisopropanol (HFIP)-Promoted Hydrodifluoroalkylation of Furans and Vinyl Ethers Using Difluorinated Silyl Enol Ethers for the Synthesis of gem-Difluorinated Ethers. J Org Chem 2025; 90:2879-2888. [PMID: 39964238 DOI: 10.1021/acs.joc.4c02420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/01/2025]
Abstract
A hexafluoroisopropanol (HFIP)-promoted hydrodifluoroalkylation of furans and vinyl ethers with difluorinated silyl enol ethers has been developed. Because of the inherent electron richer nature of furans and the poor nucleophilicity of difluorinated silyl enol ethers, the employment of simple furans as the substrates for nucleophilic dearomatization without a metal or stoichiometric chemical oxidizing reagent is challenging, especially considering the rearomatization driving force and ring fragmentation of the furan ring system. This protocol exploits the formation of oxocarbenium intermediate from furans using HFIP as a proton source to allow the nucleophilic addition of difluorinated silyl enol ethers, which provides an efficient synthetic strategy to install a gem-difluorinated group into heterocycles.
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Affiliation(s)
- Xiaogang Zhou
- School of Chemistry and Chemical Engineering, Zhejiang Sci-Tech University, Hangzhou, Zhejiang 310018, P. R. China
| | - Jing Zhang
- Advanced Research Institute and School of Pharmaceutical Science, Taizhou University, Jiaojiang, Zhejiang 318000, P. R. China
| | - Manman Sun
- Advanced Research Institute and School of Pharmaceutical Science, Taizhou University, Jiaojiang, Zhejiang 318000, P. R. China
| | - Hai-Qin Yang
- Advanced Research Institute and School of Pharmaceutical Science, Taizhou University, Jiaojiang, Zhejiang 318000, P. R. China
| | - Zhiming Wang
- Advanced Research Institute and School of Pharmaceutical Science, Taizhou University, Jiaojiang, Zhejiang 318000, P. R. China
| | - Jianguo Yang
- Advanced Research Institute and School of Pharmaceutical Science, Taizhou University, Jiaojiang, Zhejiang 318000, P. R. China
| | - Guo-Bo Huang
- Advanced Research Institute and School of Pharmaceutical Science, Taizhou University, Jiaojiang, Zhejiang 318000, P. R. China
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2
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Wang X, Zhao D, Huang JB, Shi G, Hao EJ, Ni S, Sun K. Photo-Induced Difluoromethylation-Cyclization and Domino Amination-Defluorination to 4-(Aminomethyl)-3-fluoro-quinolinones. Org Lett 2024. [PMID: 39348475 DOI: 10.1021/acs.orglett.4c03252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/02/2024]
Abstract
Herein, we report a visible light-induced difluoromethylation cyclization and subsequent amination-defluorination reaction. This protocol allows efficient to valuable 3-fluoro-quinolinones in moderate to excellent yields. A sequential difluoromethylation-cyclization-amination-defluorination mechanism was proposed based on a mechanism study. Further density functional theory (DFT) calculations revealed that the base K2HPO4 could lower the energy due to the C═O···K+ electrostatic interaction to assist the elimination process, while the six-membered transition state located in situ was essential for the cleavage of N-H and C-F bonds during this SN2'-type process.
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Affiliation(s)
- Xin Wang
- School of Pharmacy, Yantai University, Yantai 264005, P. R. China
| | - Dongyang Zhao
- School of Pharmacy, Yantai University, Yantai 264005, P. R. China
| | - Jia-Bo Huang
- College Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong Province, Shantou University, Shantou 515063, P. R. China
| | - Gangqing Shi
- School of Pharmacy, Yantai University, Yantai 264005, P. R. China
| | - Er-Jun Hao
- School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang 453007, P. R. China
| | - Shaofei Ni
- College Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong Province, Shantou University, Shantou 515063, P. R. China
| | - Kai Sun
- School of Pharmacy, Yantai University, Yantai 264005, P. R. China
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3
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Ichikawa J. Boy Meets Fluorine! J SYN ORG CHEM JPN 2023. [DOI: 10.5059/yukigoseikyokaishi.81.175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Affiliation(s)
- Junji Ichikawa
- Division of Chemistry, Faculty of Pure and Applied Sciences, University of Tsukuba
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4
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Liu YT, Fan YH, Mei Y, Li DJ, Jiang Y, Yu WH, Pan F. Chromium-Catalyzed Defluorinative Reductive Coupling of Aldehydes with gem-Difluoroalkenes. Org Lett 2023; 25:549-554. [PMID: 36637443 DOI: 10.1021/acs.orglett.3c00016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Herein, a mild and convenient defluorinative reductive cross coupling of gem-difluoroalkenes with aliphatic aldehydes has been developed to afford diverse silyl-protected β-fluorinated allylic alcohols. The reaction is operationally simple and shows good functional group tolerance with moderate to excellent yields. The utility of this method is demonstrated by converting the products into various bioactive fluorinated compounds, showing its potential applications in drug discovery and biochemistry.
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Affiliation(s)
- Yu-Tao Liu
- College of Chemistry and Materials Science, Sichuan Normal University, Chengdu 610068, People's Republic of China
| | - Yu-Hang Fan
- College of Chemistry and Materials Science, Sichuan Normal University, Chengdu 610068, People's Republic of China
| | - Yan Mei
- College of Chemistry and Materials Science, Sichuan Normal University, Chengdu 610068, People's Republic of China
| | - Dong-Jie Li
- College of Chemistry and Materials Science, Sichuan Normal University, Chengdu 610068, People's Republic of China
| | - Yan Jiang
- College of Chemistry and Materials Science, Sichuan Normal University, Chengdu 610068, People's Republic of China
| | - Wen-Hao Yu
- College of Chemistry and Materials Science, Sichuan Normal University, Chengdu 610068, People's Republic of China
| | - Fei Pan
- College of Chemistry and Materials Science, Sichuan Normal University, Chengdu 610068, People's Republic of China
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5
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Steric-switched defluorofunctionalization selectivity: controlled synthesis of monofluoroalkene-masked medium-sized heterocyclic lactams and lactones. Sci China Chem 2021. [DOI: 10.1007/s11426-021-1135-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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6
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Ye ZP, Hu YZ, Guan JP, Chen K, Liu F, Gao J, Xiao JA, Xiang HY, Chen XQ, Yang H. Photocatalytic Cyclization/Defluorination Domino Sequence to Access 3-Fluoro-1,5-dihydro-2 H-pyrrol-2-one Scaffold. Org Lett 2021; 23:4754-4758. [PMID: 34061549 DOI: 10.1021/acs.orglett.1c01477] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
We herein report an unprecedented photoinduced cyclization/defluorination domino process of N-allylbromodifluoroacetamide with cyclic secondary amines. Consequently, a wide array of valuable 3-fluoro-1,5-dihydro-2H-pyrrol-2-ones were facilely prepared from readily available starting materials under mild conditions. Preliminary mechanistic investigations suggest that a radical chain propagation and amine-promoted defluorination pathway are presumably involved in this transformation.
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Affiliation(s)
- Zhi-Peng Ye
- College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, P. R. China
| | - Yuan-Zhuo Hu
- College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, P. R. China
| | - Jian-Ping Guan
- College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, P. R. China
| | - Kai Chen
- College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, P. R. China
| | - Fang Liu
- College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, P. R. China
| | - Jie Gao
- College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, P. R. China
| | - Jun-An Xiao
- College of Chemistry and Materials Science, Nanning Normal University, Nanning 530001, Guangxi, P. R. China
| | - Hao-Yue Xiang
- College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, P. R. China
| | - Xiao-Qing Chen
- College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, P. R. China
| | - Hua Yang
- College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, P. R. China
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7
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Zeng H, Cai Y, Jiang H, Zhu C. Two C(sp 3)-F Bond Activation in a CF 3 Group: ipso-Defluorinative Amination Triggered 1,3-Diamination of (Trifluoromethyl)alkenes with Indoles, Carbazoles, Pyrroles, and Sulfonamides. Org Lett 2021; 23:66-70. [PMID: 33321040 DOI: 10.1021/acs.orglett.0c03708] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
A novel strategy enabled cleavage of two C(sp3)-F bonds in a CF3 group is reported. Triggered by ipso-defluorinative amination, this 1,3-diamination of (trifluoromethyl)alkenes with indoles, carbazoles, pyrroles, and sulfonamides gave acyclic 1,3-diamine products bearing a monofluoroalkene moiety in high yields with good to excellent Z/E selectivities. Preliminary mechanistic studies enable the isolation of the reaction intermediate and indicate that a unique sequential ipso-/γ-selective defluorinative amination pathway is involved in this transformation.
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Affiliation(s)
- Hao Zeng
- Key Laboratory of Functional Molecular Engineering of Guangdong Province, School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510640, P. R. China
| | - Yingying Cai
- Key Laboratory of Functional Molecular Engineering of Guangdong Province, School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510640, P. R. China
| | - Huanfeng Jiang
- Key Laboratory of Functional Molecular Engineering of Guangdong Province, School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510640, P. R. China
| | - Chuanle Zhu
- Key Laboratory of Functional Molecular Engineering of Guangdong Province, School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510640, P. R. China
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Morioka R, Fujita T, Ichikawa J. Facile Synthesis of 2‐Fluorobenzofurans: 5‐
endo
‐
trig
Cyclization of β,β‐Difluoro‐
o‐
hydroxystyrenes. Helv Chim Acta 2020. [DOI: 10.1002/hlca.202000159] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Ryutaro Morioka
- Division of Chemistry Faculty of Pure and Applied Sciences University of Tsukuba Tsukuba Ibaraki 305-8571 Japan
| | - Takeshi Fujita
- Division of Chemistry Faculty of Pure and Applied Sciences University of Tsukuba Tsukuba Ibaraki 305-8571 Japan
| | - Junji Ichikawa
- Division of Chemistry Faculty of Pure and Applied Sciences University of Tsukuba Tsukuba Ibaraki 305-8571 Japan
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Fuchibe K, Fushihara T, Ichikawa J. Synthesis of Ring-Fluorinated Thiophene Derivatives Based on Single C-F Bond Activation of CF 3-Cyclopropanes: Sulfanylation and 5- endo- trig Cyclization. Org Lett 2020; 22:2201-2205. [PMID: 32118451 DOI: 10.1021/acs.orglett.0c00385] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The treatment of CF3-bearing cyclopropanes with Et2AlCl generated stabilized difluorocarbocations, which underwent a nucleophilic addition of thiocarboxylic acids or thiols. The sulfur functionality was introduced at the position δ to the fluorine substituents in a regioselective manner (single activation of CF3-cyclopropanes). The formed 1,1-difluoro-1-alkenes underwent successive deesterification/5-endo-trig cyclization. Intramolecular vinylic substitution proceeded in an aprotic solvent, whereas intramolecular addition proceeded in a protic solvent to afford pharmaceutically and agrochemically promising 2-fluoro-4,5-dihydrothiophene and 2,2-difluorotetrahydrothiophene scaffolds, respectively.
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Affiliation(s)
- Kohei Fuchibe
- Division of Chemistry, Faculty of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8571, Japan
| | - Tatsuki Fushihara
- Division of Chemistry, Faculty of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8571, Japan
| | - Junji Ichikawa
- Division of Chemistry, Faculty of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8571, Japan
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Talavera M, Müller R, Ahrens T, von Hahmann CN, Braun-Cula B, Kaupp M, Braun T. Activation of tetrafluoropropenes by rhodium(i) germyl and silyl complexes. Faraday Discuss 2019; 220:328-349. [PMID: 31538175 DOI: 10.1039/c9fd00059c] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The reaction of the rhodium(i) complexes [Rh(E)(PEt3)3] (E = GePh3 (1), Si(OEt)3 (5)) with HFO-1234yf (2,3,3,3-tetrafluoropropene) afforded [Rh(F)(PEt3)3] (2) and the functionalized olefins Z-CF3CH[double bond, length as m-dash]CH(E) (E = GePh3 (4a), Si(OEt)3 (7)). Conceivable reaction pathways were assessed using DFT calculations. Reactions of [Rh(E)(PEt3)3] with HFO-1234ze (E-1,3,3,3-tetrafluoropropene) yielded the rhodium fluorido complex 2 and [Rh{(E)-CH[double bond, length as m-dash]CH(CF3)}(PEt3)3] (9) via two different reaction pathways. Using complexes 1 and 5 as catalysts, functionalized building blocks were obtained.
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Affiliation(s)
- Maria Talavera
- Humboldt-Universität zu Berlin, Department of Chemistry, Brook-Taylor-Straße 2, 12489 Berlin, Germany.
| | - Robert Müller
- Institut für Chemie, Theoretische Chemie/Quantenchemie, Technische Universität Berlin, Sekr. C7, Straße des 17. Juni 135, 10623 Berlin, Germany.
| | - Theresia Ahrens
- Humboldt-Universität zu Berlin, Department of Chemistry, Brook-Taylor-Straße 2, 12489 Berlin, Germany.
| | - Cortney N von Hahmann
- Humboldt-Universität zu Berlin, Department of Chemistry, Brook-Taylor-Straße 2, 12489 Berlin, Germany.
| | - Beatrice Braun-Cula
- Humboldt-Universität zu Berlin, Department of Chemistry, Brook-Taylor-Straße 2, 12489 Berlin, Germany.
| | - Martin Kaupp
- Institut für Chemie, Theoretische Chemie/Quantenchemie, Technische Universität Berlin, Sekr. C7, Straße des 17. Juni 135, 10623 Berlin, Germany.
| | - Thomas Braun
- Humboldt-Universität zu Berlin, Department of Chemistry, Brook-Taylor-Straße 2, 12489 Berlin, Germany.
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